Winglet Effects on the Flutter of a Twin-Engine Transport-Type Wing

Flutter characteristics of a cantilevered high aspect ratio wing with winglet were investigated. The configuration represented a current-technology, twin-engine airplane. Low- and high-speed models were used to evaluate compressibility effects through transonic Mach numbers and a wide range of mass-density ratios. Four flutter mechanisms were obtained in test and analysis from various combinations of configuration parameters. The coupling between wing-tip vertical and chordwise motions was shown to have a significant effect under some conditions. It is concluded that, for the flutter model configurations studied, the winglet-related flutter was amenable to the conventional flutter analysis techniques.